What Is Climate Change

Photo Credit: Citizens for Public Justice/Jim McIntyre

Climate change is widely recognized as the most urgent problem facing humanity. We know that human activity is warming the Earth. And we know we have the knowledge, technologies, and resources to solve the problem, in ways that support the most vulnerable nations and communities.

Earth’s atmosphere is part of a global system that keeps the temperature of the planet within a habitable range. Since the dawn of the Industrial Revolution, humans have been altering the composition of the atmosphere by burning fossil fuels, including coal, oil, and gas. The resulting carbon dioxide (CO2) builds up in the atmosphere, creating the greenhouse effect. The greenhouse effect traps energy from the sun and raises the temperature of the Earth, and this rising temperature is what most people mean when they refer to global warming or climate change. Other important greenhouse gases include methane produced mainly by natural gas production and livestock, nitrous oxide from nitrogen-based fertilizers, and hydrofluorocarbons.

The wide-ranging impacts of climate change are already being felt: economically, environmentally, and socially. All of these impacts are connected, so that worsening one problem can contribute to another. That also means that tackling greenhouse gas emissions can create cascading benefits in different areas.

We still have time to choose a future that prevents the worst impacts of climate change, by making a rapid transition to (incredibly affordable) renewable energy sources and phasing out fossil fuels. But time is short.

Entire ecosystems are already changing, and many species are going extinct because their habitats are changing faster than they can adapt.

Our civilization will have to go through rapid, profound changes to mitigate the worst of climate change and adapt to climate impacts that have already started to occur.

But if we get this right, the climate crisis also points to the massive opportunity to create jobs in a more just, green economy.

Love Bill Nye? Check out his helpful explanation of climate change in this video from the The Climate Reality Project: